Packet technology is applied very widely in network communication. Various information, such as voice, audio or other data, are transmitted in the network after being encoded using the packet technology, such as VoIP (voice over Internet Protocol) and so on. The frame information loss of voice and audio resulted from the limitation of the transmission capacity of the information transmitting end, the packet information frame not arriving at the buffer area of the receiving end in a designated delay time, or network congestion and so on causes the quality of the synthetic voice and audio at the decoding end to reduce rapidly, so it needs to use some technologies to compensate for the data of frame loss. The frame loss compensator is precisely a technology which alleviates the reduction of voice and audio quality due to the frame loss. Currently there are many technologies for the frame loss compensation, but most of these technologies are suitable for voice frame loss compensation, while few related technologies for audio frame loss compensation.
The simplest existing method for audio frame loss compensation is a method of repeating the MDCT signal of the last frame or mute replacement. Although the method is simple to implement and has no delay, the compensation effect is average. Other compensation methods, such as GAPES (gap data amplitude phase estimation technology), convert a MDCT coefficient to a DSTFT (Discrete Short-Time Fourier Transform) coefficient. But the methods are of high complexity and large expense of memory. 3GPP performs the audio frame loss compensation with a shaping noise insertion technology, and the method has a good compensation effect for a noise-like signal but a rather worse compensation effect for a multiple-harmonic audio signal.
In general, most of the disclosed audio frame loss compensation technologies have unapparent effects, or are of high calculation complexity and excessively long delay time.